Saw a fix for zip evaporation on youtube where you find a wide rubber band and put that around the lighter - covering the seam. Looking for a rubber-band now!
There was a nutter in my unit during my time in service; he used to keep his zippo inside of a section of inner-tub covering the whole lighter. Even stowed it up a sleeve of his wetsuit. When he wanted to light up, he just rolled it back and flipped it open.
I still use a zippo (pipe insert) and don't find that there is a detectable flavour from the fluid as long as I'm not chugging too hard on a light. Lengthening the wick is a must, especially for deep bowls.
For butane options I do also have some ST Dupont clones and a Dunhill rollagas. Those Dunhill's are pretty fantastic tbh a great design and easily tweakable/maintainable.